In reinforced concrete and stone structures of considerable length, dangerous self-stresses appear due to shrinkage and temperature effects, as well as due to uneven settlement of foundations. An example is the external walls of buildings, which, due to seasonal temperature changes, periodically receive increasing tensile or compressive deformations. As a result, the walls of the building may break into two or more parts, depending on the length of the building. Additional stresses in structures from uneven settlement of supports arise when building foundations are placed on dissimilar soils or when foundation pressures on the foundations are unequal.

In order to reduce their own stresses from temperature changes, concrete shrinkage and settlement of supports, reinforced concrete and stone building structures are divided along the length and width into separate parts (deformation blocks) using temperature-shrinkage and settlement joints. Temperature-shrinkage seams are used to cut buildings up to the top of the foundation, and sedimentary seams - including the foundation. This is due to the fact that the temperature and humidity conditions of the foundations fluctuate slightly, so small intrinsic stresses arise in it from shrinkage and temperature changes. In buildings made of monolithic concrete, expansion joints are also working joints, i.e., places to pause concrete laying work for a long time.

The total width of the expansion joints depends on the size of the expansion blocks of the building and possible temperature fluctuations. Calculations show that when constructing buildings in conditions average temperature their deformation blocks can be separated by seams 0.5 cm wide; they may even come into close contact, since due to concrete shrinkage, the seams themselves will open and form a gap sufficient to lengthen the longitudinal structures of the blocks as the temperature rises. If structures are erected at a relatively low temperature, then the joint width is usually 2...3 cm.

Buildings or structures that are rectangular in plan are usually divided into equal parts by seams. In buildings with extensions, it is convenient to place expansion joints in the incoming corners; with different number of storeys - at the junction of the low part with the high one (Fig. 148), and when new buildings or structures adjoin old ones - at the junction points. In seismic areas, expansion joints are also used as anti-seismic joints.

Expansion joints in enclosing structures are solved in a relatively uniform manner, which cannot be said about load-bearing frame structures. The simplest design solutions for expansion joints are. In one-story buildings this is achieved by installing paired columns

Expansion joints in frame buildings are most often formed by installing double columns and paired beams (Fig. 149, a). Such seams are the most expensive and are recommended for high-rise buildings with heavy or dynamic loads. In panel buildings, seams are made by installing paired transverse walls. When supporting floor beams on walls, it is advisable to create an expansion joint using sliding support(Fig. 149.6).

In monolithic iron concrete structures expansion joints are made by freely supporting the end of the beam of one part of the building on the beam console of another part of the building (Fig. 149, c);

in console expansion joints the contacting parts must be made strictly horizontal, since otherwise, due to jamming of the seam, both the console and the part of the beam lying on it can be damaged (Fig. 150, a). The reverse slope of the supporting surface of the console is especially dangerous. Approximate designs of expansion joints in walls and ceilings are shown in Fig. 150, in, g.

Sedimentary joints (when new buildings adjoin old ones, in places where high parts of a building meet low ones, when erecting buildings on heterogeneous and subsiding soils) are arranged using paired columns resting on independent foundations, or installed in the gap between two parts of the building (with independent foundations ) simply supported liner slabs or beam structures(Fig. 150.6). The latter solution is most often used in prefabricated structures.

Sealing interpanel seams - quality work according to the rules!

Residents of panel houses, suffering from damp, freezing walls in winter, honestly, don’t think about how moisture penetrates inside the building? When mold and mildew form on the walls, a person’s natural reaction is to fight the mold and mildew, and not the root cause that led to the formation of the fungus.

As practice shows, no means will help remove fungus from the walls of an apartment until high-quality sealing of interpanel seams is carried out in accordance with all rules and regulations.

Only sealing seams and joints in panel houses will return warmth to apartments and get rid of damp walls, mold and mildew on them.

Industrial climbers of our company carry out fast and high-quality sealing of panel seams and joints according to new technology“warm seam”, guaranteeing not only quality and reliability, but also durability of sealing. The “warm seam” technology is a high-quality and quite labor-intensive work according to all the rules, which is carried out in three stages.

At the first stage, specialists carefully clean all interpanel seams and joints of the slabs from old destroyed sealant, paint residues, cement chips and dirt accumulated in the cracks and cracks of the slabs. Only dry and clean seams guarantee high quality sealing.

Therefore, industrial climbers attach such important the stage of preparing seams for sealing. Only after all the seams and joints have been prepared in the most thorough manner does the sealing of the seams begin.

It should be noted that in the process of sealing using the “warm seam” technology, our specialists use only environmentally friendly and high-quality materials. Such materials include Macroflex sealant, Vilaterm polyurethane foam insulation and Oxyplast sun protection mastic.

A significant advantage of these materials is not only their quality and reliability, but also their low prices. Next stage repair work- compaction and then insulation of interpanel seams and joints. On final stage All seams are treated with water-repellent and sun-protective mastics, protecting them from the adverse effects of the external environment. Sealing seams in panel houses using the “warm seam” technology is a guarantee that the apartments will be warm and dry, and such phenomena as mold and mildew will not be reported. damp walls can be forgotten forever.

Order the services of industrial climbers for sealing interpanel, balcony and window seams, as well as for insulation and repair of balconies and loggias, as a collective of residents, they can panel house, as well as any owner of an apartment in individually. After the order is accepted, industrial climbers will come to the site to study the degree of destruction of the interpanel seams.

Based on this information, the scope of work is determined, the consumption of materials is determined, and an estimate is drawn up. Note that today it is only 30 linear meters.

For corner apartments this minimum has been increased to 45 linear meters. Order fulfillment times, as a rule, do not exceed 1-2 working days. Orders for external repair work in high-rise buildings accepted from organizations.

Question from a client

Hello.

Please tell me, what are these cracks (or just loose joints) along the gutters?

Cracks from 1st to 5th floors.

The house is brick.

How dangerous are they and how much will your repair work cost?

Good afternoon, Irina!

The cost of the work is 480 rubles per linear meter (approximately what you sent in the photographs, you have 3 seams of 17 meters each, approximately 25 tr.) But most likely for each such seam there is a second seam on the other side of the house (if they are already sealed during operation)

So I understand that you sent a photo of the courtyard part of the house and the front part of the house was renovated at one time....

Sincerely, Vadim Snyatkov

thank you very much for the information.

I'll tell the neighbors.

Manual for SNiP II-22-81 Expansion joints in walls and ceilings of stone buildings:

Home / Technologies / Regulatory documentation / Manual for SNiP II-22-81 Expansion joints in the walls of buildings

/ SN 420-71 Building codes and regulations for sealing seams
/ VSN 19-95 Instructions for the technology of sealing butt joints of panels of external walls of residential buildings
/ VSN 40-96 Instructions for performing work on sealing joints of external walls and window blocks
/ TR 94.10-99 Technical regulations for work on sealing joints of external enclosing structures
/ TR 94.07-99 Technical regulations for work on sealing joints of external enclosing structures
/ Technological map 3 Sealing of joints of external wall panels, performed during repairs of series 1-464"
/ Manual for SNiP II-22-81 Expansion joints in the walls of buildings, sealing expansion joints
/ Methods for sealing open and closed vertical joints of panels and their construction
/ TR 196-08 Technical recommendations on the technology of sealing and sealing joints of external wall panels
/ 44-03 TK Technological map. Sealing joints of external enclosing structures
/ VSN-119-75 instructions for sealing joints during the repair of prefabricated buildings
/ VSN 42-96 Instructions for window sealing technology using sealants
/ TR 116-01 Technical recommendations on the technology of sealing joints of external wall panels
/ Guidelines for quality control and testing of joints of external wall panels of large-panel houses
/ Typical technical solutions for increasing the thermal protection of buildings of the I-335 series
/ TR 95.07-99 Technological regulations for sealing joints of external enclosing structures
/ Table 53-21. Repair and restoration of sealing of joints of external wall panels and jointing of wall panels and floor panels
/ VSN 170-80 “Instructions for sealing vertical and horizontal joints of external wall panels of the P44/16 series
/ VSN 17-94 Instructions for mechanized technology for thermal insulation of joints of external wall panels of residential buildings with phenol-formaldehyde foam

Sealing expansion joints in external walls

Expansion joints Manual for SNiP II-22-81. A guide to the design of masonry and reinforced masonry structures

Date of text update: 10/01/2008

Status - active

Available now for viewing: 100% text. Full version document.

The document was approved by: TsNIISK im. V.A. Kucherenko from 1985-08-15

The document was developed by: TsNIISK im. V.A. Kucherenko 109389, Moscow, 2nd Institutskaya st., 6

NIISF Gosstroy USSR 127238, Moscow, Lokomotivny proezd, 21

Bashkirgrazhdanproekt

EXPANSION JOINTS

7.220. Expansion joints in the walls and ceilings of stone buildings are arranged in order to eliminate or reduce negative influence temperature and shrinkage deformations, settlement of foundations, seismic effects, etc.

7.221. Temperature-shrinkage joints are installed in places of possible concentration of temperature and shrinkage deformations, which can cause ruptures, cracks, as well as distortions and shifts of the masonry in structures that are unacceptable under operating conditions and durability.

7.222. The distances between temperature-shrinkage seams should be determined by calculation in accordance with the instructions of the appendix. 11.

The maximum distances between temperature-shrinkage joints in unreinforced external walls are taken in accordance with the instructions in paragraph , without taking into account the effects of temperature and shrinkage.

The distances specified in paragraph can be increased by reinforcing the masonry walls according to calculations.

Note. Cutting buildings with expansion joints in accordance with the requirements of the item reduces, but does not completely eliminate, thermal forces in the walls and ceilings. Therefore, in all cases, it is necessary to carry out a calculation check for the effect of temperature and shrinkage of individual units and interfaces of structures in which the concentration of temperature deformations and stresses is possible. The check is carried out in accordance with the instructions in app. 11.

7.223. Expansion joints in the walls of buildings with extended (20 m or more) steel or reinforced concrete inclusions or reinforcement (beams, lintels, floor slabs, reinforcing belts, etc.) are installed at the ends of the reinforced sections and inclusions, where concentration usually occurs temperature deformations and the formation of cracks and through breaks. Examples of expansion joints in these cases are shown in Fig. 60.

7.224. Expansion joints in the walls may not be installed provided that the masonry is reinforced in places where the reinforcement breaks or at the ends of the connection according to the calculation in accordance with the instructions of the appendix. 11.

In buildings with longitudinal load-bearing walls and prefabricated floors, which have frequent (every 1-2 m) cutting with transverse seams (see Figure 60, b), expansion joints with opening widths of no more than 2.5 m and the absence of extended reinforced inclusions may not be arranged, regardless of the length and number of floors of the building and the climatic conditions of the development area.

In this case, the opening of cracks in the walls and at the ends of reinforced lintels should not exceed the permissible values ​​​​according to table. 1 adj. 11.

7.225. The design of expansion joints in walls, ceilings and coverings of masonry buildings must meet the following requirements:

a) expansion joints in external and interior walls It is recommended to arrange floors and coverings (roofs) of buildings in one plane for the entire height of the building, excluding foundations, the cutting of which is optional; the issue of cutting only external or only internal walls with seams is decided separately with sufficient justification;

b) expansion joints in the walls must coincide with the joints in reinforced concrete or steel structures(ceilings, frames, strapping beams, etc.) that have a structural connection with the walls (filling, anchors, etc.), and must also coincide with other types of seams (sedimentary, seismic, installation, etc.) ;

c) expansion joints must have sufficient horizontal mobility (up to 10-20 mm) both during compression and expansion of the seam, and the design of the seam must ensure convenient installation, control and repair of sealing devices and insulation;

Crap. 60. Examples of installing expansion joints in the walls of stone buildings with reinforced inclusions (ceilings, beams, reinforced belts)

a - when reinforced inclusions are located in the middle part of the building; b - the same, in the extreme part; in - at reinforced concrete covering(roof) with a seam; g - with foundation beams with a seam; d - examples of embedding reinforced inclusions in masonry walls; 1 - overlap; 2 - reinforced concrete beam; 3 - metal beam; 4 - fittings; 5 - expansion joint in reinforced elements (slabs, beams); 6 - the same, in stone walls(dotted line) ; 7 - prefabricated floors with transverse seams

d) the width of the expansion joint is determined by calculation, but must be at least 20 mm;

e) expansion joints of external walls must be water- and airtight and frost-proof, for which they must have insulation and reliable sealing in the form of elastic and durable seals made of easily compressible and non-crumpling materials (for buildings with dry and normal operating conditions), metal or plastic expansion joints made of corrosion-resistant materials (for buildings with damp and wet conditions).

7.226. Sealing of expansion joints in external walls is carried out using metal and plastic expansion joints (Fig. 61, e, b) or using elastic seals (Fig. 61, c, d).

The seams of the internal walls are sealed using sealants. The use of compensators for these purposes must be justified.

Crap. 61. Installation of expansion joints in the external walls of buildings

a, b - with dry and normal operating modes; c, d - with wet and wet modes; 1 - insulation (roofing felt and roofing felt with insulation or poroizol, gernite); 2 - plaster; 3 - jointing; 4 - compensator; 5 - antiseptic wooden slats 60´60 mm; 6 - insulation; 7 - vertical joints filled with cement mortar

Depending on humidity conditions interior spaces compensators can be made of corrosion-resistant sheet metal(galvanized or stainless steel, copper, lead, etc.) or special plastics (polyvinyl chloride, neoprene, butyl, etc.). The ends of the expansion joints must be tightly embedded in the concrete or masonry walls, as shown in Fig. 61.

The use of sealants made of elastic porous materials (poroizol, gernite, etc.), as well as bags of roofing felt or roofing felt with elastic insulation between layers of these materials (see drawing 61, a, b) for sealing seams in external walls is allowed only for buildings with dry and normal humidity conditions with the width of expansion joints not exceeding 30 mm. In this case, an expansion joint is made in the wall. with masonry ledges (tongue and quarter, see drawing 61, a, b).

When using expansion joints, joints are laid without ledges. The seams are sealed using sealants on both sides (outside and inside).

Examples of the installation of expansion joints in reinforced concrete insulated and non-insulated roofs of buildings are shown in Fig. 62.

7.227. When supporting the floors on load-bearing transverse walls, crossbars of frame frames, etc., expansion joints are arranged in the form of two paired walls (Fig. 63, d, b), crossbars and frame columns, or in the form of sliding seams of floor slabs resting on cantilevered outlets , embedded in transverse walls or in special fines (Figure 63, c, d). To ensure sliding under the slab supports, two layers should be laid roofing iron, as shown in Fig. 63.

Crap. 62. Examples of installing expansion joints in reinforced concrete roofs

a - with a concrete ridge; b - with a ridge made of brickwork; c - without ridge; 1 - wooden antiseptic plugs; 2 - compensator made of roofing iron; 3 - board 50´120 mm; 4 - concrete class B12.5; 5 - roll roofing; 6 - brickwork with mortar grade 100; 7 - bracket (-3´40) after 500 mm; 8 - reinforced concrete slabs

Crap. 63. Expansion joints in buildings with transverse load-bearing walls

a, b - in the form of two paired walls; c - in the form of sliding support of floor slabs in the groove of the transverse wall; d - the same, on a cantilever slab embedded in the wall; 1 - insulation (roofing felt or roofing felt with insulation or poroizol, gernite); 2 - two layers of galvanized iron; 3 - flexible connection - limiter with a diameter of 6-8 mm every 1.5-2 m; 4 - cover plate; 5 - reinforced concrete console

7.228. Expansion joints in buildings with longitudinal load-bearing walls are installed at internal transverse walls or partitions (Figure 64).

Crap. 64. Expansion joints in buildings with longitudinal load-bearing walls

a - at the junction of the longitudinal wall with the transverse one; b - the same, at the transverse partition; 1 - insulation (roofing felt or roofing felt with insulation or poroizol, gernite); 2 - jointing; 3 - flashing; 4 - tarred tow; 5 - partition

7.229. The plaster in places where expansion joints are installed must be expanded (Fig. 64, a, b).

In residential, public and household premises It is recommended to cover expansion joints on the room side with strips (see drawing 64).

Frequently asked questions about seam sealing:
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Expansion joints are widely used in many industrial areas. We are talking about high-rise construction, construction of bridge structures and other industries. They represent a very important object element, and select required type dilation design will vary depending on:

• the magnitude of static and thermohydrometric changes;
• the magnitude of a certain transport load and the required level of travel comfort during operation;
• from the conditions of detention.

The purpose of the expansion joint is to reduce the load on individual parts of structures in places of expected deformations that can occur due to fluctuations in air temperature, as well as seismic phenomena, unexpected and uneven sedimentation of the soil and other influences that can cause their own loads that reduce the load-bearing properties of structures. In visual terms, this is a cut in the body of the building; it divides the building into several blocks, giving these a certain elasticity to the structure. To ensure waterproofing, the cut is filled with suitable material. It could be various sealants, waterstops or putty.

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Installing an expansion joint is the prerogative of experienced builders, so such a responsible task should be entrusted exclusively to qualified specialists. The construction team must have adequate equipment for proper installation of the expansion joint - the longevity of the entire structure depends on this. It is necessary to provide for all types of work, including installation, welding, carpentry, reinforcing, geodetic, concrete laying. The technology for installing an expansion joint must comply with accepted specially developed recommendations.

The maintenance of expansion joints in general does not present any difficulties, but requires periodic inspections. Special control must be carried out in the spring, when pieces of ice, metal, wood, stone and other debris can get into the dilatation space - this can serve as an obstacle to the normal functioning of the seam. In winter, care should be taken when using snow removal equipment, since its actions can damage the expansion joint. If a malfunction is detected, contact the manufacturer immediately.

Since hydraulic structures made of reinforced concrete or concrete (for example, dams, shipping buildings, hydroelectric power stations, bridges) are of considerable size, they undergo force impacts of various origins. They depend on many factors, such as the type of base, production conditions and others. Ultimately, thermal shrinkage and sedimentary deformations may occur, risking the appearance of cracks of various sizes in the body of the structure.

In order to ensure the safety of the solidity of the structure to the maximum extent, the following measures are applied:

• rational cutting of buildings with temporary and permanent joints depending on both geological and climatic conditions
• creation and maintenance of normal temperature conditions during the construction of buildings, as well as during further operation. The problem is solved by using low-shrinkage and low-heat grades of cement, its rational use, pipe cooling, thermal insulation concrete surfaces
• increasing the level of homogeneity of concrete, achieving its adequate tensile strength, strength for reinforcement in places where cracks may occur and axial tension

At what point do the main deformations of concrete buildings occur? Why are expansion joints needed in this case? Changes in the building body can occur during construction under high temperature stress - a consequence of the exotherm of hardening concrete and fluctuations in air temperature. In addition, at this moment concrete shrinkage occurs. During the construction period, expansion joints can reduce excessive loads and prevent further changes that could be fatal to the structure. The buildings seem to be cut along their length into separate sectional blocks. Expansion joints serve to ensure high-quality functioning of each section, and also eliminate the possibility of forces occurring between adjacent blocks.

Depending on the service life, expansion joints are divided into structural, permanent or temporary (construction). Permanent seams include temperature cuts in structures with a rock foundation. Temporary shrinkage joints are created to reduce temperature and other stresses; thanks to them, the structure is cut into individual columns and concreting blocks.

There are a number of types of expansion joints. Traditionally, they are classified according to the nature and nature of the factors causing deformation in structures. Here they are:

• Temperature
• Sedimentary
• Antiseismic
• Shrinkage
• Structural
• Insulating

The most common types are temperature and sedimentary expansion joints. They are used in the vast majority of constructions of various structures. Expansion joints compensate for changes in the body of buildings that occur due to changes in ambient temperature. More susceptible to this ground part buildings, so cuts are made from the ground level to the roof, thereby not affecting the fundamental part. This type seams cuts the building into blocks, thus ensuring the possibility of linear movements without negative (destructive) consequences.

Sedimentary expansion joints compensate for changes due to uneven various types of structural loads on the ground. This is due to differences in the number of floors or big difference in the mass of ground structures.

The anti-seismic type of expansion joints is provided for the construction of buildings in seismic zones. The arrangement of such sections makes it possible to divide the building into separate blocks, which are independent objects. This precaution allows you to effectively counteract seismic loads.

IN monolithic construction Shrinkage seams are widely used. As concrete hardens, a decrease in monolithic structures is observed, namely in volume, but at the same time excess internal tension is formed in the concrete structure. This type of expansion joint helps prevent the appearance of cracks in the walls of the structure as a result of exposure to such stress. When the wall shrinkage process is completed, the expansion joint is tightly sealed.

Insulation joints are installed along columns, walls, and around the foundation for equipment in order to protect the floor screed from possible transfer of deformation resulting from the building structure.

Construction joints act as shrinkage joints; they involve small horizontal movements, but in no case vertical ones. It would also be good if the construction seam corresponded to the shrinkage seam.

It should be noted that the design of the expansion joint must correspond to the plan of the developed project - we're talking about about strict compliance with all specified parameters.

Designers of bridge structures, first of all, advocate the excellent versatility of expansion joints and their design, which would allow one or another system of joints to be used practically without changes on any type of bridge structures (dimensions, diagrams, bridge deck, materials for manufacturing spans, etc.) .

If we talk about expansion joints installed in road bridges, the following criteria should be taken into account:

• Waterproof
• Durability and reliability of operation
• The amount of operating costs (it should be minimal)
• Small values ​​of reactive forces that are transmitted to supporting structures
• Possibility of uniform distribution of gaps in the spaces of suture elements over wide temperature ranges
• Moving bridge spans in all possible planes and directions
• Noise emissions in different directions when moving vehicles
• Simplicity and ease of installation

In the span structures of small and medium-sized bridge structures, expansion joints of filled and closed types when moving the ends of spans, up to 10-10-20 mm, respectively.

Based on the type, the following classification of expansion joints in bridges is obvious:

Open type. This type of seam involves an unfillable gap between the composite structures.

Closed type. In this case, the distance between the adjacent structures is closed by the roadway - a coating laid without the necessary gap.

Filled type. IN closed seams The coating, on the contrary, is laid with a gap, because of this, the edges of the gap, as well as the filling itself, are clearly visible from the roadway.

Overlapping type. In the case of a covered expansion joint, the gap between the connecting structures is blocked by some element at the upper level of the roadway.

In addition to the type characteristic, expansion joints of bridge structures are divided into groups according to their location in the roadway:

• under the tramway
• in the curb
• between sidewalks
• on the sidewalks

This is the standard classification of bridge expansion joints. There are also secondary, more detailed divisions of seams, but all of them must be subordinate to the main grouping.

Judging by the experience of operating bridges in Western Europe, it is obvious that the service life of a bridge structure (any) depends almost one hundred percent on the strength and quality of expansion joints.

What are the types of expansion joints between buildings? Experts classify them according to a number of characteristics. This may be the type of structure being serviced, the location (device), for example, expansion joints in the walls of the building, in the floors, in the roof. In addition, it is worth considering the openness and closedness of their location (indoors and outdoors, on outdoors). A lot has already been said about the generally accepted classification (the most important, covering all the most characteristic signs of expansion joints). It was adopted on the basis of the deformations that it is intended to combat. From this point of view, the expansion joint between buildings can be temperature, sedimentary, shrinkage, seismic, or insulating. Depending on the current circumstances and conditions between buildings, apply various types expansion joints. However, you should know that all of them must correspond to the initially specified parameters.

Even at the building design stage, specialists determine the location and size of expansion joints. This occurs taking into account all expected loads causing deformation of the structure.

When constructing an expansion joint, it is necessary to understand that it is not just a cut in the floor, wall or roof. With all this, it must be correctly designed from a constructive point of view. This requirement is due to the fact that during the operation of structures, expansion joints take on enormous loads. If an excess occurs bearing capacity seam, there is a risk of cracks. This, by the way, is a fairly well-known phenomenon, and special profiles made of metal can prevent it. Their purpose is expansion joints - the profiles seal them and provide structural reinforcement.

The seam between buildings serves as a kind of connection between two structures that are close to each other, but have different foundations. As a result, the difference in the weight load of the structures may have a negative impact, and both structures may develop unwanted cracks. To avoid this, a rigid connection with reinforcement is used. In this case, it is necessary to make sure that both foundations have already settled properly and are sufficiently resistant to the upcoming loads. The construction of the expansion joint is carried out in strict accordance with generally accepted procedures.

Expansion joint between walls

As you know, walls are the most important element in the structure of a structure. They perform a load-bearing function, taking on all falling loads. This is the weight of the roof, floor slabs, and other elements. It follows from this that the reliability and durability of a building largely depends on the strength of the expansion joint between the walls. Moreover, the comfortable operation of interior spaces also depends on the walls (load-bearing structures), which perform the important function of fencing from the outside world.

You should know that the thicker the wall material, the higher the requirements are placed on the expansion joints installed in them. Despite the fact that externally the walls appear monolithic, in reality they have to endure various types of loads. The causes of deformation may be:

• air temperature changes
• the soil under the structure may settle unevenly
• vibration and seismic loads and much more

If cracks form in load-bearing walls, then this may threaten the integrity of the entire building as a whole. Based on the foregoing, expansion joints are the only way to prevent changes in the body of structures that could become fatal.

In order for the expansion joint in the walls to function correctly, it is necessary, first of all, to carry out the design work correctly. Thus, the calculation of actions must be carried out at the building design stage.

The main criterion for the successful operation of an expansion joint is the correctly calculated number of compartments into which it is planned to cut the building to successfully compensate for stress. According to the established quantity, the distance that must be taken into account between the seams is also determined.

As a rule, in walls with a load-bearing function, expansion joints have an interval of approximately 20 meters. If we are talking about partitions, then a distance of 30 meters is allowed. In this case, builders are required to take into account areas of concentration of internal stresses. The distance is determined by the type of expected expansion joints, which in turn depend on the factors causing changes in the body of the structure.

In addition, at the initial stage of design in the walls of structures, the width of the cut for expansion joints is taken into account with special care. This parameter has important functional significance, as it determines the amount of expected transverse displacement structural elements buildings. You should also think about ways to seal expansion joints in advance.

Expansion joints in industrial buildings

The length of industrial structures, as a rule, is almost always greater than that of civil buildings, so the construction in such joints becomes great value. In industrial buildings, specialists provide expansion joints according to their purpose. They can be antiseismic, sedimentary and even temperature.

Expansion joints in frame buildings cut the building into separate blocks, as well as all structures resting on it. In industrial buildings of mass construction, as a rule, expansion joints are installed, which in turn are divided into longitudinal and transverse. The distance between seams in industrial buildings is determined according to the structural design of the building, as well as the climatic conditions of construction and the air temperature inside the room. If we are talking about reinforced concrete one-story structures of industrial buildings, then the gap between the seams is allowed without calculating the rise of 20%.

Transverse expansion joints on one-story industrial buildings are made on paired columns without taking into account the insert. In multi-storey buildings - with or without an insert and also on paired columns. It is worth noting that seams without insertion are more technologically advanced, since they do not require additional enclosing elements. Today, expansion joints are made in the format of an elastic arch from mineral wool slabs of medium hardness. They are crimped with galvanized roofing steel - cylindrical aprons. In the area where the expansion joint is installed, the carpet is reinforced with several layers of fiberglass.

Temperature longitudinal joints in one-story buildings are installed on 2 rows of columns with an insert; its width, depending on the connection in adjacent spans, is considered to be from 500 to 1000 mm. If the longitudinal expansion joint is combined with different heights of adjacent spans, therefore other sizes of inserts are accepted. The same conditions are observed in places where perpendicular spans are mutually adjacent to one another.

If we are talking about industrial buildings with a constructed reinforced concrete skeleton without special overhead cranes, expansion longitudinal joints can be installed on such columns as single ones. Such a seam is easy to install, thereby allowing you to not take into account additional elements in walls and coverings, as well as paired columns or rafter structures. The same can be said for industrial buildings without cranes with mixed or metal frames.

Many years of experience working with housing and communal services enterprises have shown the need for periodic explanations various technologies maintenance of buildings and systems of functioning of various structural elements of buildings.

Types of expansion joints

Expansion joints are divided according to their purpose into temperature, shrinkage, settlement, expansion and seismic and represent a through section of the building into separate blocks to reduce the load on structural elements in places of various deformations.

In our climate zone, the first two types are most often found. Expansion joints can be seen on houses longer than four entrances, and sometimes more often, and they serve to increase the elasticity of the building in the off-season, when the ambient temperature, and therefore the building, changes.

Shrinkage joints are used primarily in houses consisting of sections of different number of storeys, which means they have different shrinkage after construction.

In other words, expansion and shrinkage joints are needed to prevent the building from cracking due to temperature fluctuations and during shrinkage of the building.

Of course, the expansion joint must be protected from snow, moisture, dirt, and the formation of drafts inside it. To do this, the seam is insulated and sealed. The choice of material for insulation depends primarily on the width of the seam, and the method of sealing the seam depends on the planned service life and the funds available for its repair.

The most obvious seems to be to fill the joint with Viloterm and plaster it, as is done in many new buildings. This method as simple as it is, it is also short-lived, since the plaster in the expansion joint is not able to withstand the load placed on it and inevitably first cracks and then crumbles.

Viloterm has shown its fragility in the absence of combining it with polyurethane foam.

Seam insulation options

Let's sort it out possible options insulation and sealing depending on the width of the seam.

If the width is small, it would be optimal to use classic polyurethane foam, protected from sun rays In its condition, it is second only to expanded polystyrene in durability.

With a seam width of 30 to 50 mm, a combination of polyurethane foam and viloterma is optimal. Viloterm will save foam and add plasticity to the joint, and the foam will create a margin of safety and will not allow the Viloterm to take a constant shape during the displacement of parts of the building, and therefore will not allow cracks to appear in the expansion joint.

The natural question is: why can’t the seam be completely filled with polyurethane foam?

Firstly, with a designed seam width of more than 30 mm, a significant displacement of building elements relative to each other is also taken into account, which means there is a need to ensure proper ductility of the insulation.

Secondly, foam is much more expensive than expanded polystyrene and viloterma, and, as a result, if the seam is completely filled with polyurethane foam only, the cost per linear meter will increase significantly.

Seam sealing options

The temperature-shrinkage joint is sealed either with a two-component sealant or sealed with a galvanized expansion joint.

The sealant can be used on seams of small to medium thickness. It is important to use a two-component polyurethane sealant because it is more flexible than acrylic sealants and is more durable. The disadvantage of this method is that it is relatively unaesthetic, since a two-component sealant cannot be applied in a perfectly even layer due to its properties. The advantage is the cost of creating a seam, since applying sealant is less labor-intensive than installing an expansion joint.

The use of sealant is most justified for shrinkage joints, especially for new buildings, where the displacement of building elements relative to each other has not yet passed its most active stage. The sealant will crack over time, but without damaging the building's façade, especially if the building is insulated with the currently widely used “wet façade.”

The most durable way to seal an expansion joint is to seal the joint with a galvanized expansion joint. It is extremely important to use not just galvanized sheet, but to use metal profile with expansion joint reinforcement. Its service life is limited only by the aging of the metal. If you use simple galvanizing without deformation bending, then over time it will be torn out of the wall due to the lack of minimum tensile elasticity.

Any building structures, regardless of what material they are made of (brick, monolithic reinforced concrete or building panels), change their geometric dimensions when the temperature changes. When the temperature drops, they contract, and when the temperature rises, they naturally expand. This can lead to cracks and significantly reduce the strength and durability of both individual elements(for example, cement-sand screeds, foundation blind areas, etc.), and the entire building as a whole. To prevent these negative phenomena, an expansion joint is used, which must be installed in appropriate places (according to regulatory construction documents).

Vertical temperature-shrinkage joints of buildings

In long buildings, as well as buildings with different amounts floors in certain sections, SNiP provides for the mandatory arrangement of vertical deformation gaps:

• Temperature - to prevent the formation of cracks due to changes in the geometric dimensions of the structural elements of the building due to temperature changes (average daily and average annual) and concrete shrinkage. Such seams are brought to the level of the foundation.
• Settlement joints that prevent the formation of cracks that can form due to uneven settlement of the foundation caused by unequal loads on its individual parts. These seams completely separate the structure into separate sections, including the foundation.

The designs of both types of seams are the same. To create a gap, two paired transverse walls are erected, which fill heat-insulating material, and then waterproofed (to prevent precipitation from entering). The width of the seam must strictly correspond to the design of the building (but be at least 20 mm).

The spacing of temperature-shrinkage joints for frameless large-panel buildings is standardized by SNiP and depends on the materials used in the manufacture of the panels (class of concrete compressive strength, grade of mortar and diameter of the longitudinal load-bearing reinforcement), the distance between the transverse walls and the annual difference in average daily temperatures for a particular region . For example, for Petrozavodsk (the annual temperature difference is 60°C), temperature gaps must be located at a distance of 75÷125 m.

IN monolithic structures and buildings constructed using the prefabricated monolithic method, the pitch of transverse temperature-shrinkage joints (according to SNiP) varies from 40 to 80 m (depending on the structural features of the building). The arrangement of such seams not only increases the reliability of the building structure, but also allows for the gradual casting of individual sections of the building.

Note! In individual construction, the arrangement of such gaps is used extremely rarely, since the length of the wall of a private house usually does not exceed 40 m.

IN brick houses seams are arranged similarly to panel or monolithic buildings.

In reinforced concrete building structures, the dimensions of floors, as well as the dimensions of other elements, can vary depending on temperature changes. Therefore, when installing them, it is necessary to arrange expansion joints.

The materials for their manufacture, dimensions, locations and installation technology are indicated in advance in the design documentation for the construction of the building.

Sometimes such seams are structurally made to be sliding. To ensure sliding in those places where the floor slab rests on the supporting structures, two layers of galvanized roofing iron are laid under it.

Temperature expansion joints in concrete floors and cement-sand screeds

When pouring a cement-sand screed or arranging a concrete floor, it is necessary to isolate all building structures (walls, columns, doorways, etc.) from contact with the poured mortar throughout its entire thickness. This gap performs three functions simultaneously:

• At the stage of pouring and setting the mortar works as a shrinkage joint. The heavy wet solution compresses it; as the concrete mixture gradually dries, the dimensions of the poured canvas decrease, and the material filling the gap expands and compensates for the shrinkage of the mixture.
• It prevents the transfer of loads from building structures concrete surface and vice versa. The screed does not put pressure on the walls. The structural strength of the building does not change. The structures themselves do not transfer the load to the screed, and it will not crack during operation.
• When there is a temperature difference (and they necessarily occur even in heated rooms), this seam compensates for changes in the volume of the concrete mass, which prevents it from cracking and increases its service life.

To create such gaps, a special damper tape is usually used, the width of which is slightly greater than the height of the screed. After the solution has hardened, its excess is cut off with a construction knife. When they settle in concrete floors shrinkage seams (if the finishing flooring not provided), the polypropylene tape is partially removed and the groove is waterproofed using special sealants.

In rooms of a large area (or when the length of one of the walls exceeds 6 m), according to SNiP, it is necessary to cut longitudinal and transverse temperature-shrinkable joints with a depth of ⅓ of the thickness of the fill. An expansion joint in concrete is made using special equipment(gasoline or electric joint cutter with diamond discs). The pitch of such seams should not be more than 6 m.

Attention! When filling heated floor elements with mortar, shrinkage joints are installed to the entire depth of the screed.

Expansion joints in foundation blind areas and concrete paths

Foundation blind areas, designed to protect the foundation of a house from the harmful effects of precipitation, are also susceptible to destruction due to significant temperature changes throughout the year. To avoid this, seams are installed to compensate for the expansion and contraction of concrete. Such gaps are made at the stage of construction of blind area formwork. Transverse boards (20 mm thick) are attached to the formwork around the entire perimeter in increments of 1.5÷2.5 m. When the solution has set a little, the boards are removed, and after the blind area has completely dried, the grooves are filled with damping material and waterproofed.

All of the above applies to the arrangement concrete paths on the street or parking spaces nearby own home. However, the step of deformation gaps can be increased to 3÷5 m.

Materials for arranging seams

Materials intended for arranging seams (regardless of type and size) are subject to the same requirements. They must be resilient, elastic, easily compressible and quickly recover their shape after compression.

It is designed to prevent cracking of the screed during its drying and compensate for loads from building structures (walls, columns, etc.). A wide selection of sizes (thickness: 3÷35 mm; width: 27÷250 mm) of this material allows you to equip almost any screed and concrete floors.

A popular and easy-to-use material for filling deformation gaps is a cord made of foamed polyethylene. There are two types of it on the construction market:

• solid sealing cord Ø=6÷80 mm,
• in the form of a tube Ø=30÷120 mm.

The diameter of the cord must exceed the width of the seam by ¼÷½. The cord is installed in the groove in a compressed state and filled with ⅔÷¾ of the free volume. For example, to seal 4 mm wide grooves cut in a screed, a Ø=6 mm cord is suitable.

Sealants and mastics

Various sealants are used to seal seams:

• polyurethane;
• acrylic;
• silicone.

They come in both one-component (ready-to-use) and two-component (they are prepared by mixing two components immediately before use). If the seam is of small width, then it is enough to fill it with sealant; if the gap width is significant, then this material is applied on top of the laid cord made of foamed polyethylene (or other damping material).

Various mastics (bitumen, bitumen-polymer, compositions based on raw rubber or epoxy with additives to impart elasticity) are used mainly for sealing external expansion gaps. They are applied on top of the damping material placed in the groove.

Special profiles

IN modern construction expansion joints in concrete are successfully sealed using special compensation profiles. These products come in a variety of configurations (depending on application and joint width). For their manufacture, metal, plastic, rubber are used, or several materials are combined in one device. Some models in this category must be installed during the process of pouring the solution. Others can be installed in the groove after the base has completely hardened. Manufacturers (both foreign and domestic) have developed a wide range of model range such devices, both for outdoor use and for indoor installation. The high price of the profiles is compensated by the fact that this method of sealing gaps does not require their subsequent waterproofing.

In conclusion

Correct arrangement of temperature, expansion, expansion and settlement joints significantly increases the strength and durability of any building; parking spaces or garden paths with concrete covering. When using high-quality materials for their manufacture, they will last for many years without repair.